U.S. Sen. Claire McCaskill could write a chapter about her own unforced errors. A March tweet from the Missouri Democrat continues to haunt her.

McCaskill denied ever speaking to or meeting with Russian Ambassador Sergey Kislyak. The claim, now proven false, has gained new life with revelations that she attended a reception at Kislyak’s residence and donated to a foundation that counts him as a board member.

Premium content for only $0.99

At the time, Attorney General Jeff Sessions was facing intensifying scrutiny for not disclosing meetings with the Russian ambassador during his confirmation hearings.

Sessions’ defense was that the meetings didn’t have anything to do with the election but were related to his role on the Senate Armed Services Committee. The explanation was fuzzy and raised more questions, given that others close to President Donald Trump had failed to ‘fess up to meetings and connections to the Russians.

No one was pressing McCaskill to detail any meetings she’d had during her years on the Armed Services Committee. But she jumped in anyway, sending out her sweeping denial via Twitter in an attempt to cast more doubt on Sessions’ meetings with Kislyak.

Shortly after, reporters ferreted out other tweets by McCaskill showing that she had spoken with Kislyak on at least a couple of occasions. One was a meeting with Kislyak about Russia possibly ending U.S. adoptions and the other was a brief phone call with the ambassador about the Iran nuclear deal.

Now, a CNN report has revealed McCaskill’s attendance at the 2015 reception at the ambassador’s residence.

McCaskill didn’t completely own her initial flub. She admitted the mistake. But then she tried to explain the discrepancy, saying that she wanted to make clear that she’d never met with the ambassador in her role as a member of the Armed Services Committee.

In acknowledging the latest flap, McCaskill has explained that yes, she attended a black-tie reception for her longtime mentor and fellow Missourian, former Rep. James Symington. McCaskill did not interact with the ambassador, according to a spokesperson.

The senator attended the event to honor Symington. She once interned for the Democrat and helped with his campaign as a student at the University of Missouri.